Many engines produce power by combusting hydrocarbon fuel. Such engines may produce undesirable emissions, including oxides of nitrogen (NOx). The air/fuel ratio used by an engine combusting hydrocarbon fuel may affect the quantity of NOx produced by the engine. Generally, the leaner the air/fuel ratio an engine combusting hydrocarbon fuel uses, the less NOx emissions the engine will produce. Unfortunately, some fuels, such as natural gas, may combust less readily at leaner air/fuel ratios, which may decrease the likelihood of the engine consistently combusting the fuel successfully (i.e. not misfiring).
U.S. Pat. No. 6,397,790 to Collier, Jr. (“the '790 patent”) discloses a method of fueling an engine that involves directing natural gas through a reformer to reform at least part of the natural gas into hydrogen and carbon monoxide before supplying it to the engine. The '790 patent discloses mixing the hydrogen, carbon monoxide, and any unreformed methane that exit the reformer with air and supplying the mixture to the engine. The '790 patent discloses that the hydrogen and carbon monoxide in the reformed natural gas help prevent the engine from misfiring.
Although the '790 patent discloses fueling an engine at least partially with reformed natural gas that includes hydrogen and carbon monoxide to help prevent the engine from misfiring, certain disadvantages persist. Additionally, reforming natural gas to form hydrogen and carbon monoxide requires energy that could otherwise serve other valuable purposes. Accordingly, in some applications and/or circumstances, preventing an engine from misfiring exclusively with the method taught by the '790 patent may consume an undesirable amount of energy reforming the natural gas.
The engine and methods of the present disclosure solve one or more of the problems set forth above.